An area of ongoing research and development is in improving security of networks. There are many techniques available to secure a network. An example of such a technique is requiring the use of passwords to access a given network. However, passwords have well-known weaknesses. For example, people often have trouble remembering passwords; so they use passwords that are the names of their pets or children. When longer, more complicated passwords are required, people often resort to writing the password down, which a malicious person can find and use to access the network. Even good passwords that are memorized can be picked up and potentially decrypted (or even worse, read in the clear) by an eavesdropper. So using a password, without more, might be considered inadequate.
Other limitations of the relevant art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings.